d) Run the regression model from (c). Remember to create dummy variables for the months and to use only pre-event data. i. What can we learn from the statistical significance level of the coefficients for October and September? ii. The actual value of Air (air revenue passenger miles) in January 1990 was 35-153577 billion. What is the residual for this month, using the regression model? Report the residual in terms of air revenue passenger miles